ESRL Participates in ICEALOT Cruise

March 17, 2008

Researchers from the NOAA Earth System Research Laboratory (ESRL) will
participate in the International Chemistry Experiment in the Arctic Lower
Troposphere (ICEALOT) research cruise: A Springtime Study of Aerosol
Properties and Atmospheric Chemistry over an Ice-Free Region of the Arctic.
The cruise will take place in the eastern Arctic (in the Greenland,
Norwegian, and Barents Seas) from March 19 - April 24, 2008 with the
overarching purpose of addressing scientific questions related to the
sources, transport, and climatic impacts of anthropogenic aerosol and gas
phase species. Using a variety of instrumentation, ESRLŐs Physical Sciences
Division (PSD) will take measurements of cloud liquid water path, cloud
micro-physical properties, turbulent fluxes, and high-resolution
turbulence. The ESRL Chemical Sciences Division (CSD) will collect data on
a broad range of climate-relevant gases and aerosols. Measurements will be
taken of long-lived compounds such as carbon dioxide, shorter-lived species
such as ozone and its precursors, aerosols such as black carbon, and
aerosol properties such as light absorption and scattering.

The ICEALOT research cruise is part of the IPY activity, "Polar Study using
Aircraft, Remote Sensing, Surface Measurements and Models, of Climate,
Chemistry, Aerosols, and Transport (POLARCAT)." POLARCAT is a series of
experiments at different times of the year that will follow pollution
plumes of different origin as they are transported into the Arctic and
observe the chemistry, aerosol processes, and radiation effects of these
plumes. The experiments will also take advantage of the long residence
times of pollutants in the more stable Arctic atmosphere to study aging
processes by targeting air masses that have spent considerable time in the
Arctic. The Arctic will, thus, also serve as a natural laboratory for
investigating processes that cannot be studied elsewhere in such isolation.

Three important aspects of this experiment to NOAA are the springtime
sources and transport of pollutants to the Arctic, evolution of aerosols
and gases into and within the Arctic, and climate impact of aerosols and
ozone in the Arctic. Measurements made of aerosol and gas phase species
associated with ship emissions will serve as a "baseline" before the
possibility of an increase in ship traffic as a result of the decrease in
ice coverage is realized along the Northern Sea Route and Northwest
Passage. A better understanding of the climatic effects of the short lived
pollutants is required to guide mitigation strategies and, in particular,
to determine to what extent reducing concentrations of aerosols and
tropospheric ozone in the source regions will reduce the rate of warming in
the Arctic.